Envelop.



A. H.GUSTAF SON. ENVELOP.

APPLICATION FILED MAR. Z1. 19!?- Patented Dec. 11, 191?.

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Anrnun H. eUsTArsoN, "or oHIoAGo, ILLINOIS.

'ENVELOP;

T 0 dll whomit may concern: g 7

Be it known that I, ARTHUR vH. GUSTAF- son, a citizen of the United States, and-a resident of Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Envelops; and I do hereby declare that the following is a full, clear, and exact description thereof, reference bcing had to the accompanying drawings, and'to the characters of reference marked thereon, whichffo-rm apart oi' this specification. t v a y l. 'lhisinvention relates to improvements in safety envelops of that class wherein the closing flap is interlocked to the body of the envelop in such a way that when said vflap closed and the interlocked parts of the body are engaged, the said-flap can not be opened again without tearing the sheet from which the envelop is made and thereby leaving traces which show that the envelop has been tampered with. v

Among the objects of theinvention is to provide a simple and efiective envelop of this character, which can be made at acost not substantially greater than the ordinary sealed envelop,.and a' construction wherein the locking device on' .the closing fiapand the. envelop are not onlycertain in'resp'e'ct to their locking :action butfare formedon or by parts which possess sufiicient strength or ruggedness to withstand hard usage.

The blank from which the envelop ismade comprises a main or' central'section 10, two I end fiapsll, 11 a side flap 1'2 and a closing flap 13. The several flaps are joined .to ,the central portion of the envelop blank along fold lines indicated ,bythe broken lines.

The end flaps'll are of special form, each comprising a wide innerportion having an oblique edgel which springs from the cen tral portion of the blank at the fold line between said central portion and the flap 12, and a relatively elongated terminal 15, the

upper edge of which eiit'ends in] prolongation] Specification of IiettersPatent. Patented Dec, 11', 1917; i Application filedMarch 27,1917. s rial na szssz. i

f the fold 'linelbet'ween closingflap' ia'and the main or 'central. portion @of the blank. The flap 12 s generally triangular as ih standardenvelops. Instead of terminating ina sharp, point, the terminallii of said flap has the form ofa relatively shortjrectangu lar extension 16... v

The fclosing flap 13 isgformed" atitsouter edge with a substantially rectangular exten- $1011 WhiC i PIOVided with end wing f18 I I and a i wm lgflwt rejoi edto e x.

tensionalong the fold 'linesindicated. Each of the said terminal portions 15 oftheiend fiap is provided with a slit, 20,;ind1 at the ends of each slitis a.triangularfnotchfQl.

The extension 16 of the flap '12 is likewise,

provided with a similar r slit 22 having end notches 23. v a Y 1n folding-up the blank 'to produce the envelop the'en'd flaps 11 are first folded inwardly over the central portion 10 of'the blank I with their elongated terminals or wings 15 one over the other and said terminalsareof suchlength that each reache's'l a distancebeyon d the transverse center line of V the envelop. U Pasteis applied to the over.-

"lapping partsiof the end flap terminals 50 as to paste them together. Thereafter the flap, 121s folded upwardly over-the, end flaps and flis pastedl at its oblique marginal portions 14 to theflend flaps, theffiap being gu'mmed for this purpose and-the extension 16 isalso pasted fiat uponthe-overlapping terminals 15 of the end flaps. 'When said terminals 15 and the eX tension 16 are thus assembled theseve'ral slits 20' and 22 are" brought into register, as well also as are the notches 23 at the ends of said slits. -VVhe'n "sa'ld'fiap's are thus folded and pasted the slits 2O and 22 andthenotc'hes 2 l and 23, 1a're brought into registration to PITOClllC/ifl/ through slit through the three plyjwa'll of the envelop; and sa'id three ply'wall, thus pasted, produces a sufficiently heavy wall structure at the slit to resist tearingout jof the-slit. I v

The end and" side wings 18,;19,f'respec'- tively, of the closing, flap tongue or extension 17 are folded inwardly onfsa'id tongue in the way shown in Figs. 2 and Sto pro- ,duce a. ocket 24 which opens inwardlytotie base of the flap, and the said wings are pasted together in their overlying parts. The multi layer construction produces a tongue of suflicient stifiness to enable it to be readily inserted into" the slit of the envelop wall. 7 Said pocket is of such width that it fits the lip formed in the multiple envelop Wall above the locking slit so.

as to interlock with said lip, the notches 21, 23 permitting the pocket to slide over I the parts are so interlocked they can not be detached for the reason that the free edge of th pocket can not be made to pass the locking lip .at the slit. Any successful attempt .to release the locking tongue will therefore result either in tearing the tongue or the envelop wall at the end of the locking slit and leave evidence of tampering. I

If desired, and especially with long envelops, small patches of gum 25 may be applied to the oblique margins of the closing flap so as to avoid opening of said flap awayfrom' the envelops when the flap is closed to such an extent as to permit other envelops in the mail bag entering'beneath the flap margin in a mannertending to tear said flap.

' The blank from which I the envelop is formed also constitutes a feature of my invention as is hereinafter claimed. g It is to be understood that some variations may be made in the structural detail without departure from the spirit of my invention and that the invention is not limited to the specific detail shown except as to claims wherein such details are specifically set forth and as imposed by the prior art.

I claim as-my invention:

1. An envelop having a closing flap provided with a locking tongue formed with a pocket that isclosed at its ends and at one side and open at its inner side, the wall of said envelop being provided with a slit to receive said tongueand at one side of said Slit with a 11p which enters said pocket.

' 2. An envelop having a closing flap provided witha locking tongue formed with a pocket that is closed at its ends and at one side and open at. its inner side. thewall of saiclfenvelop being provided with a slit to rece ve said tongue and at the ends of said slit with notches to form at one side of said W'itnesses slit a lip to enter and interlock with said pocket.

3. An envelop having a closing flap and formed with a multiple wall, the plys of which are pasted together and pierced with a locking slit having at one side a locking looking tongue to enter said'slit, saidtongue providedwith' end andside wings which are folded over the tongue in overlapping relation to each other and pasted'together to form a pocket which interlocks with said lip.

'' 5. An envelop comprising-a main portion,

two end and a side folding flap which are folded over the main portion and in overlapping relation to each other, and are pasted together at their overlapping portions, said flaps being provided with slits a tongue to enter said slit and having members'that are folded and pasted together to form a pocket to interlock with the edge of said slit, and with said notches. H e

6. The blankfor theenvelop described comprising a central section, three foldable sections provided with extensions each having a locking slit formed with notched portions at the end thereof to provide a lip on the upper edge of the slit, and a closing section provided with a pocketadapted for cooperation with said lips when the blank is assembled. V

7. An envelop having a plurality of foldable sections adapted to be assembled to produce a multi-ply wall provided with a slit having a downwardly extending lip therein,

and a closing section having an extension adapted for insertion through said slit, said extension being provided with a pocket adapted for the reception of said lip, whereby withdrawal of the said extension is prevented.

Inwitness that I claim the foregoing as my invention, I hereunto append my signature in the presence of two witnesses at Chicago, Illinois, this 26th day of March, 1917.

ARTHUR H. GUSTAFSON.

W. L. HALL, KATIIARIXE GERLACH.

Copies of this patent may be obtained for five cents each. by addressing the Commissioner of Patents,

- Washingtonyl). C. i 

